Birkner Ewa, Zalejska-Fiolka Jolanta, Kasperczyk Aleksandra, Kasperczyk Sławomir, Grucka-Mamczar Ewa, Stawiarska-Pieta Barbara, Birkner Katarzyna
Department of Biochemistry in Zabrze, Medical University of Silesia, Katowice, Poland.
Biol Trace Elem Res. 2007 Winter;120(1-3):179-94. doi: 10.1007/s12011-007-0070-4.
Significant disorders of liver metabolic pathways enzymes after high-cholesterol diet could give information on liver steatosis development. This process could probably also be inhibited by some compounds, as examined in rabbits. Forty-two male rabbits were served a high-cholesterol diet (2 g%) (0.67 g/kg b.m./24 h) with addition of d,l-methionine (70 mg/kg b.m./24 h) or seleno-d,l-methionine (12.5 microg/kg b.m./24 h) or alpha-tocopherol (10 mg/kg b.m./24 h) for 3 months to compare the protection effect of used compounds on liver metabolism and steatosis. At the beginning and every month, blood was taken. After the experiment was completed, livers were dissected for histological examinations. The concentration of total cholesterol (t-CH), triacylglycerol (TG), and the activities of aldolase (ALD), sorbitol dehydrogenase (SDH), glutamate dehydrogenase (GLDH), lactate dehydrogenase (LDH), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) were determined. Plasma t-CH and TG concentrations were significantly higher in all experimental groups vs control group. Blood serum AST and ALT activities did not undergo change but there were observed not significant increase in the CH group vs control group. Activities of SDH, GLDH, and LDH increased in blood serum and decreased in the liver in all experimental groups. Activities of LDH and SDH increased in the liver in the CH+Met group vs CH group. ALD activity decreased in the liver only in the CH and CH+Se groups. This data support a lipotoxic model of cholesterol-mediated hepatic steatosis. Prolonged administration of high-cholesterol diet not only disturbs the structure of cell membranes, which is expressed by decreased activity of enzymes in the liver and the migration of those enzymes to plasma but as well leads to steatosis of the liver, which has been confirmed by histological examinations. The applied compounds appear to have a varying influence upon the activity of enzymes determined in serum and liver. Obtained results showed a beneficial influence of methionine and vitamin E supplementation on liver steatosis development.
高胆固醇饮食后肝脏代谢途径酶的显著紊乱可能为肝脂肪变性的发展提供信息。正如在兔子身上所研究的那样,这个过程可能也会被某些化合物抑制。42只雄性兔子被喂食高胆固醇饮食(2 g%)(0.67 g/kg体重/24小时),并添加d,l-蛋氨酸(70 mg/kg体重/24小时)或硒-d,l-蛋氨酸(12.5 μg/kg体重/24小时)或α-生育酚(10 mg/kg体重/24小时),持续3个月,以比较所用化合物对肝脏代谢和脂肪变性的保护作用。在实验开始时和每个月采集血液。实验结束后,解剖肝脏进行组织学检查。测定总胆固醇(t-CH)、三酰甘油(TG)的浓度以及醛缩酶(ALD)、山梨醇脱氢酶(SDH)、谷氨酸脱氢酶(GLDH)、乳酸脱氢酶(LDH)、天冬氨酸转氨酶(AST)和丙氨酸转氨酶(ALT)的活性。与对照组相比,所有实验组的血浆t-CH和TG浓度均显著升高。血清AST和ALT活性未发生变化,但与对照组相比,CH组有不显著的升高。所有实验组血清中SDH、GLDH和LDH的活性升高,肝脏中这些酶的活性降低。与CH组相比,CH+Met组肝脏中LDH和SDH的活性升高。仅在CH组和CH+Se组肝脏中ALD活性降低。这些数据支持胆固醇介导的肝脂肪变性的脂毒性模型。长期给予高胆固醇饮食不仅会扰乱细胞膜结构,这表现为肝脏中酶活性降低以及这些酶向血浆中的迁移,还会导致肝脏脂肪变性,这已通过组织学检查得到证实。所应用的化合物似乎对血清和肝脏中测定的酶活性有不同影响。获得的结果表明补充蛋氨酸和维生素E对肝脏脂肪变性的发展有有益影响。